Power supply of non-linear loads includes; three major equipments; a Power transformer, a rectifier and an electrolyzer. Each of these three components, generate their specific harmonics and combination of the abovementioned harmonic sources in the electrochemical plant. Therefore this causes serious problems due to huge amount of DC current.
Harmonic is an unwanted phenomenon in electrical industry which causes various difficulties for consumers and power supply networks. Harmonic reduction at generating sources; is the basic and desired target for specialists; especially at high-power electrolyzer industries.
The harmful effects of harmonics can be described in the following categories: Firstly on power transformers, it causes overheating and consequently reduction in production. Secondly has an effect on upstream networks; which results in problems with the AC power supplier. Thirdly it has an effect on electrical equipment installed in plants, such as abnormal operation of motors.
The highest sources of harmonics generation, are the industries which apply AC to DC converters with a non-linear, high-rated power loads, since non-linear loads are also sources of harmonic generation. Various solutions are already applied for harmonic reduction. Some of them such as a harmonic filter, a PWM and a Multi-pulse rectifier are not perfectly applicable for high-power sources, and others such an OLTC are complicated and extremely expensive.
On the other hand survey of former inventions at aforementioned industries; shows that:
1) A harmonic filter has no effect on power transformer's overheating, and also has a probability of dangerous resonance.
2) A Multi-pulse rectifier requires complicated transformers, with high losses and is not suitable for high-power application.
3) Other techniques, which were useful for other applications, were not applicable for non-linear high-power loads.
In such situations and abstinence of techniques resolving the above issues and shortcomings, the present invention will be a remarkable solution. Also since the harmonic distortion of thyristors, still has their costs and problems; this condition led me to find a way for changing the future use of rectifiers in those industries; which suffer from huge amount of harmonics.